JP6866310B2 - Image display device and its control method - Google Patents

Description

The present invention relates to a synchronized display of a tomographic image of a living tissue and an X-ray image.

Endovascular treatment is performed using high-performance catheters such as balloon catheters and stents. Intravascular ultrasound (IVUS) is used for preoperative diagnosis in this endovascular treatment or for confirmation of progress after surgery. In addition, an optical coherence tomography (OCT) is used instead of IVUS, and an optical coherence tomography (SS-OCT) using wavelength sweep is used as an improved version of OCT. Has been done. Intravascular diagnostic devices that can acquire tomographic images such as IVUS and OCT have more detailed information on the lesion site confirmed by the X-ray device, such as the stenosis rate in blood vessels, the presence of plaques in branches, and the distribution of calcification. Used to obtain.

When the doctor determines that treatment is necessary, the doctor determines the details of treatment such as where to position the stent edge by observing the vascular tomographic image obtained by the above-mentioned intravascular diagnostic apparatus. When treating the treatment site determined in this way, the doctor performs treatment such as placement of a balloon or a stent while observing an X-ray image (angio image) obtained by an X-ray device. Therefore, it is a very important factor in the treatment to understand which position on the X-ray image the treatment site determined by confirming the vascular tomographic image, that is, the position where the balloon or the stent is installed, corresponds to.

Japanese Unexamined Patent Publication No. 2013-116332

As described above, in endovascular treatment and the like, it is important to grasp the positional relationship between the obtained vascular tomographic image and the X-ray image. However, since the intravascular diagnostic device and the X-ray device are configured as different modalities, doctors rely on landmarks such as branch positions on the X-ray image corresponding to the site diagnosed by the vascular tomographic image. It is necessary to guess the position of the blood vessel and perform treatment.

In order to improve the estimation accuracy of the position on the X-ray image corresponding to the vascular tomographic image as described above, the X-ray image at the time of acquiring the vascular tomographic image is captured and the X-ray image is displayed in synchronization with the vascular tomographic image. There is an apparatus (see Patent Document 1). Generally, an X-ray opaque marker is installed in the vicinity of the sensor portion of the catheter connected to the vascular tomographic image device, and the above estimation accuracy is improved by displaying the vascular tomographic image and the X-ray image in synchronization. I'm letting you. By using this function, it is possible to visualize the vascular tomographic image and the position of the X-ray opaque marker on the X-ray image in a one-to-one correspondence.

However, when evaluating a lesion, doctors do not look only at a single vascular tomographic image and a single position on an X-ray image, but look at the entire blood vessel. In other words, as a result of confirming the vascular tomographic image, the doctor grasps the lesion range having a certain length in the long axis direction of the blood vessel, imagines the range on the X-ray image corresponding to the lesion range, and evaluates and treats it. It is carried out. With the function of simply displaying the vascular tomographic image and the X-ray image in synchronization as described above, the lesion area on the X-ray image that the doctor wants to confirm cannot be visualized, and a single vascular tomographic image is displayed. Only the position on the X-ray image can be confirmed.

The present invention has been made in view of the above problems, and makes it possible for the user to easily grasp the cross-sectional information of the vascular tomographic image identified from the plurality of vascular tomographic images and the position on the X-ray image. The purpose.

An image display device according to an aspect of the present invention that achieves the above object has the following configuration. That is,
An access means for accessing a storage means for storing a plurality of vascular tomographic images acquired while moving the probe in the axial direction of the catheter and a plurality of X-ray images taken during the movement of the probe.
An acquisition means for acquiring an X-ray image to be displayed from the plurality of X-ray images via the access means, and an acquisition means.
A specific means for identifying a vascular tomographic image from the plurality of vascular tomographic images, and
In the X-ray image to be displayed, a determination means for determining a position corresponding to the acquisition position of the specified blood vessel tomographic image on the blood vessel image corresponding to the blood vessel to which the probe has moved, and
A predetermined figure is superimposed and displayed on the X-ray image to be displayed so as to indicate the position determined by the determination means, and information based on the cross-sectional information associated with the vascular tomographic image identified by the specific means is displayed. A display control means for displaying on the means is provided.

According to the present invention, the cross-sectional information of the vascular tomographic image identified from the plurality of vascular tomographic images and the position on the X-ray image can be easily grasped.
Other features and advantages of the present invention will become apparent in the following description with reference to the accompanying drawings.

The accompanying drawings are included in the specification and are used to form a part thereof, show embodiments of the present invention, and explain the principles of the present invention together with the description thereof.
It is a figure explaining the structure of the display system by embodiment. It is a figure explaining the catheter system for acquiring a vascular tomographic image. It is a figure explaining the catheter system for acquiring a vascular tomographic image. It is a figure explaining the acquisition timing of a vascular tomographic image and an X-ray image. It is a figure which shows the composition example of the cross-sectional information associated with the vascular tomographic image. It is a flowchart explaining the overlay display processing of the tomographic image information by the display system of embodiment. It is a flowchart explaining the blood vessel detection process by Embodiment. It is a figure explaining the blood vessel position information obtained by the blood vessel detection process. It is a figure explaining the acquisition position of the blood vessel tomographic image obtained by the blood vessel detection process. It is a flowchart explaining the conversion table generation process by Embodiment. It is a figure which shows the data structure example of the conversion table. It is a flowchart explaining the synchronous display and cross-section information superimposition display processing by embodiment. It is a figure which shows the example of the synchronous display by embodiment, and the superimposition display in an X-ray image. It is a figure which shows the example of the superimposition display of the X-ray image by an embodiment. It is a figure which shows the example of the superimposition display of the X-ray image by an embodiment.

Hereinafter, an example of a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a diagram showing a configuration example of a display system that realizes synchronous display of a vascular tomographic image and an X-ray image (angio image) according to the present embodiment. In the intravascular diagnostic apparatus 100, the tomographic image generation unit 101 uses intravascular ultrasound (IVUS), optical coherence tomography (OCT), or the like based on a signal obtained from a catheter system inserted into a subject's blood vessel. Generates a tomographic image in a blood vessel (hereinafter referred to as a vascular tomographic image). The catheter system 111 is inserted close to the heart through the arteries at the base of the foot, for example, to take a tomographic image in the blood vessels around the heart of patient 10. When the intravascular diagnostic device 100 is an optical interference diagnostic device using OCT, the tomographic image generation unit 101 emits measurement light via the probe of the catheter system 111, and the reflected light is incident through the probe to cause a fault. Get the statue. On the other hand, when the intravascular diagnostic apparatus 100 is an ultrasonic tomographic imaging apparatus using IVUS, the tomographic image generation unit 101 outputs an ultrasonic signal via the probe of the catheter system 111 and outputs the reflected signal via the probe. To obtain a tomographic image by inputting.

2A and 2B are diagrams illustrating the catheter system 111. As shown in FIG. 2A, the catheter system 111 includes a guiding catheter 112, a catheter 113 containing a probe 115 for tomography, and a guide wire 114. The guiding catheter 112 has a hollow for inserting the guide wire 114 and the catheter 113. For example, when taking a tomographic image of a coronary artery, a doctor inserts a guiding catheter 112 into the vicinity of the coronary artery, and then passes a guide wire 114 through the guiding catheter 112 to send the guiding catheter 112 to the imaging site of the coronary artery. Then, the doctor sends the imaging core 117 of the catheter 113 to the imaging region of the coronary artery by feeding the catheter 113 along the guide wire 114. The catheter 113 is provided with a guide wire lumen 119, and by passing the guide wire 114 through the guide wire lumen 119, the catheter 113 can proceed along the guide wire.

FIG. 2B shows the details of the portion of reference numeral 2B (tip portion of the catheter 131) of FIG. 2A. The probe 115 for tomography includes a metal shaft 116, an imaging core 117, and an X-ray opaque marker 118. In the case of tomography by OCT, the imaging core 117 is connected to the tip of an optical fiber passing through the metal shaft 116. The imaging core 117 includes an optical component that transmits and receives measurement light from the tip of the optical fiber. On the other hand, in the case of tomography by IVUS, a signal line passing through the metal shaft 116 and an imaging core 117 including an ultrasonic transducer that transmits and receives ultrasonic signals are connected. The metal shaft 116 moves in the axial direction of the catheter (movement in the direction of arrow 121) while being rotationally driven (rotation in the direction of arrow 120) (hereinafter referred to as pullback). The imaging core 117 also rotates with the metal shaft 116 and moves in the axial direction of the catheter. Since a tomographic image is obtained by one rotation of the imaging core, the tomographic image acquired during the movement of the rotating imaging core 117 becomes a plurality of vascular tomographic images along the vascular path. An X-ray opaque marker 118 for recognizing the position of the imaging core 117 on the X-ray image is provided between the imaging core 117 and the metal shaft 116. The X-ray opaque marker 118 may be provided on the distal end side of the imaging core 117.

Returning to FIG. 1, the tomographic image generation unit 101 stores the tomographic image (vascular tomographic image in this embodiment) obtained by IVUS or OCT in the vascular tomographic image storage unit 105. The frame rate of the tomographic image by the tomographic image generation unit 101 is about 160 to 180 Hz. The cross-sectional information generation unit 102 displays information indicating the observation result of the tomographic image input by the doctor (section designation (reference) of the lesion site, inspection result regarding calcification, etc.) and the vascular tomographic image generated by the tomographic image generation unit 101. The information obtained by automatic analysis (such as the lumen area of the blood vessel and the average diameter of the lumen) is associated with the tomographic image as cross-sectional information and stored in the vascular tomographic image storage unit 105. The intravascular diagnostic apparatus 100 and the X-ray imaging apparatus 200 are connected by a cable 104. The X-ray image acquisition unit 103 receives the X-ray image acquired by the X-ray imaging device 200 from the X-ray imaging device 200 via the cable 104 and stores it in the X-ray image storage unit 106. The vascular tomographic image storage unit 105 and the X-ray image storage unit 106 can be accessed by the image display device 300. In the present embodiment, an example is shown in which communication between the intravascular diagnostic device 100 and the X-ray imaging device 200 is performed via a cable 104 (wired), but the present invention is not limited to this, and wireless communication or the like is shown. May be used.

The X-ray imaging apparatus 200 drives the X-ray source 211 to irradiate the patient 10 with X-rays, and detects transmitted X-rays with the X-ray sensor 212 to obtain an X-ray image (for example, an angio image). The X-ray imaging apparatus 200 can transmit the obtained X-ray image to the intravascular diagnostic apparatus 100 via the cable 104. The frame rate of the X-ray image in the X-ray imaging apparatus 200 is, for example, about 7 to 30 Hz. The X-ray image acquisition unit 103 saves the X-ray image taken during the pullback (during the imaging of the vascular tomographic image) among the X-ray images sent from the X-ray imaging apparatus 200.

The image display device 300 synchronously displays the X-ray image and the vascular tomographic image, and superimposes and displays the cross-sectional information acquired on the vascular tomographic image at the position corresponding to the vascular tomographic image on the X-ray image. The "position corresponding to the vascular tomographic image" is a position on the X-ray image of the imaging core 117 when the vascular tomographic image is taken, and is also hereinafter referred to as a tomographic image acquisition position. In the image display device 300, the X-ray image reading unit 301 accesses the X-ray image storage unit 106 to read the X-ray image. The blood vessel detection unit 302 detects the blood vessel from which the vascular tomographic image has been acquired (the blood vessel to which the probe 115 has moved, hereinafter also referred to as a target blood vessel) from the X-ray image. The position of the target blood vessel detected by the blood vessel detection unit 302 is stored in the blood vessel position information storage unit 304 as blood vessel position information. The table generation unit 303 estimates the acquisition position on the target blood vessel detected by the blood vessel detection unit 302 for each frame of the blood vessel tomographic image group stored in the blood vessel tomographic image storage unit 105. Then, the table generation unit 303 generates a position conversion table in which the frame of the vascular tomographic image is recorded in association with the estimated acquisition position (indicated by the x and y coordinates on the X-ray image), and the conversion table is generated. It is stored in the storage unit 305.

The vascular tomographic image reading unit 306 accesses the vascular tomographic image storage unit 105, reads the vascular tomographic image and cross-sectional information, and provides the display control unit 307. The display control unit 307 synchronously displays the X-ray image read by the X-ray image reading unit 301 and the vascular tomographic image read by the vascular tomographic image reading unit 306 on the display 308, and is added to the vascular tomographic image. The cross-sectional information is superimposed and displayed. Each part of the image display device 300 described above may be realized by a computer executing a predetermined program, or a part or all of them may be realized by dedicated hardware.

Hereinafter, synchronous display processing and superimposed display processing of the vascular tomographic image and the X-ray image by the display system of the present embodiment having the above-described configuration will be described. First, with reference to FIG. 3A, collection of a vascular tomographic image and an X-ray image by the intravascular diagnostic apparatus 100 of the present embodiment will be described.

FIG. 3A is a diagram illustrating the timing of collecting X-ray images and vascular tomographic images according to the present embodiment. When the user instructs the start of scanning on the operation panel (not shown) of the intravascular diagnostic apparatus 100, the intravascular diagnostic apparatus 100 starts a low-speed rotation of the metal shaft 116 (and the imaging core 117) in the catheter 113. After that, when the user instructs the start of pullback ready on the operation panel of the intravascular diagnostic apparatus 100, the intravascular diagnostic apparatus 100 starts high-speed rotation of the metal shaft 116 (and the imaging core 117). When the imaging core 117 is rotated at high speed, it is possible to start taking a tomographic image while pulling back.

After starting the pullback ready, the user instructs the start of X-ray imaging from an operation panel (not shown) of the X-ray imaging apparatus 200. When the start of X-ray imaging is instructed, the X-ray imaging apparatus 200 irradiates X-rays from the X-ray source 211 and photographs an X-ray image (for example, an angio image) by the X-ray sensor 212. The obtained X-ray image is transmitted to the intravascular diagnostic apparatus 100 via the cable 104. However, in the present embodiment, the X-ray image group 321 received by the time the pullback start is instructed is not stored in the X-ray image storage unit 106.

The user instructs the start of X-ray photography and then starts the flash. In the flash, a contrast medium is injected into the blood vessel. Then, when the user instructs to start pullback, the intravascular diagnostic apparatus 100 starts pullback of the imaging core 117 and also starts generation of a vascular tomographic image. The vascular tomographic image group 311 during the pullback operation is stored in the vascular tomographic image storage unit 105. Further, the X-ray image group 322 acquired by the X-ray imaging apparatus 200 during this pullback operation is stored in the X-ray image storage unit 106 by the X-ray image acquisition unit 103. The stored X-ray image shows the region of interest of the blood vessel being pulled back with the contrast medium, and the X-ray opaque marker 118 moving with the pullback of the imaging core 117. The vascular tomographic image used for the synchronous display is a vascular tomographic image from the start of pullback in the vascular tomographic image group 311 to the vascular tomographic image in which the end of the guiding catheter 112 is detected (in this embodiment, the N frame). It is assumed that a vascular tomographic image exists). The X-ray image used for the synchronous display is an M-frame X-ray image corresponding to the N-frame vascular tomographic image in the X-ray image group 322. The ratio of N to M is the ratio of the frame rate of the vascular tomographic image to the frame rate of the X-ray image.

In the above, the X-ray image group 321 before the start of pullback is not saved, but the X-ray image group 321 and the X-ray image group 322 may be saved in the X-ray image storage unit 106. In this case, information indicating that the image is being pulled back is added to each X-ray image of the X-ray image group 322, and the X-ray image reading unit 301 draws the X-ray image being pulled back based on this information. It should be read out.

Subsequently, the cross-section information generation unit 102 generates cross-section information for each of the N-frame vascular tomographic images, adds the cross-sectional information to the vascular tomographic image, or stores the cross-sectional information in the vascular tomographic image storage unit 105 in association with the vascular tomographic image. To do. FIG. 3B shows how cross-sectional information is associated with each of the N-frame vascular tomographic images.

As shown in FIG. 3B, the cross-section information generated by the cross-section information generation unit 102 includes information that is automatically analyzed and detected for each vascular tomographic image and information that is generated in response to a doctor's input. The automatically detected cross-sectional information is the average lumen diameter obtained from the lumen area of the blood vessel and the lumen area (assuming the lumen area is S, the average lumen diameter Da = 2 × √ (S / π)). The maximum diameter, minimum diameter, and eccentricity of the lumen can be mentioned. These cross-sectional information is acquired for all vascular tomographic images and associated with each vascular tomographic image. In addition, the cross-section information generation unit 102 automatically detects the branch portion of the blood vessel, and automatically uses information indicating whether the vascular tomographic image is the base side end portion or the peripheral side end portion of the branch portion as cross-section information. Generate. Further, the cross-section information generation unit 102 detects the presence of the stent in the vascular tomographic image and generates information indicating the presence or absence of the stent as cross-section information.

Further, the cross-sectional information generation unit 102 associates various information input by the doctor by observing the vascular tomographic image, for example, information on calcification, reference position, and bookmarks with the vascular tomographic image as cross-sectional information. For example, the doctor can observe the vascular tomographic image and indicate the extent of calcification, and the cross-section information generator 102 indicates that calcification is present in the vascular tomographic image corresponding to the indicated area. Associate the information shown. Further, the doctor can measure the thickness of calcification and the angle of calcification from the vascular tomographic image to each vascular tomographic image, and the cross-sectional information generation unit 102 associates these measurement results with the vascular tomographic image as cross-sectional information. Further, the doctor can add a bookmark to the desired vascular tomographic image while observing the vascular tomographic image, and the cross-sectional information generation unit 102 uses the information indicating whether or not the bookmark is added as the cross-sectional information in the vascular tomographic image. Associate. Furthermore, the doctor can specify the start and end vascular tomographic images of the lesion area, and the cross-sectional information generation unit 102 indicates that the cross-sectional information is a reference position for each vascular tomographic image corresponding to the specified lesion area. To associate.

After collecting the vascular tomographic image (vascular tomographic image group 311) and the X-ray image (X-ray image group 322) and storing the cross-sectional information as described above, the image display device 300 displays the vascular tomographic image and the X. Synchronous display of line images and superimposition display of cross-sectional information. Hereinafter, the synchronous display superimposition display by the image display device 300 will be described with reference to the flowchart of FIG.

First, in step S401, the blood vessel detection unit 302 detects the blood vessel (target blood vessel) for which the blood vessel tomographic image has been taken for each of the X-ray images of the M frame. Hereinafter, the detection process of the target blood vessel (hereinafter, blood vessel detection process) by the blood vessel detection unit 302 will be described in more detail with reference to the flowchart of FIG.

In the blood vessel detection process, first, in step S501, the X-ray image reading unit 301 reads the first X-ray image of the M-frame X-ray image group stored in the X-ray image storage unit 106. Then, in step S502, the blood vessel detection unit 302 normalizes the peripheral region of the marker estimation position on the X-ray image as the processing target region. In this step, normalization is performed so that the minimum and maximum values of the luminance value in the processing target area are the minimum and maximum values of the effective bit width. The marker estimation position in the first frame of the X-ray image is the marker initial position given by the user, and the marker estimation position calculated in step S509 (described later) is used for the subsequent frames. The initial marker position can be specified by the user, for example, by specifying the position of the X-ray opaque marker 118 on the X-ray image read in step S501 by operating the mouse of the user.

Next, in step S503, the blood vessel detection unit 302 filters the processing target region to detect an image candidate of the X-ray opaque marker 118. The X-ray opaque marker 118 looks like a small black circle on the X-ray image. Therefore, the blood vessel detection unit 302 detects a black spot candidate by using, for example, a convolution filter or a frequency filter that can emphasize the black spot.

In step S504, when a plurality of black spot candidates are obtained in step S503, the blood vessel detection unit 302 executes a labeling process on the detected black circles, calculates a correlation value for each label, and has the largest correlation value. Select a black dot candidate as a marker. The blood vessel detection unit 302 uses the selected position of the black spot candidate (for example, the position of the center of gravity) as the marker position. As the correlation value, for example, the following can be used.

-Distance correlation: A correlation value that increases as the distance between the estimated marker position (x0, y0) and the position of the candidate black spot (x, y) increases. For example, e = 1 / √ ((x0−x) ² + Obtained by (y0−y) ² ).
-Area ratio: A correlation value indicating whether the area (size) of the sunspot candidate is close to the size of a typical X-ray opaque marker, for example, ΔS = Sj / Sr (Sj is the size of the currently targeted black spot, Sr is determined by the size of a typical opaque marker). Whether the size of a typical X-ray opaque marker is a fixed value or the size of a black dot detected from the initial position of the marker given by the user, the size of the X-ray opaque marker detected in the previous frame You may use the size.
-Brightness difference: A correlation value indicating a change in brightness between frames. This correlation value increases as the change in brightness at the position of the black point candidate between frames (the brightness value of the black point candidate in the i + 1 frame and the change in brightness at the corresponding position of the image in the i-frame) increases. For example, it is obtained by ΔI = (Ii + 1-Ii) + 2 (σi + 1-σi). Here, Ii + 1 is the average luminance of one black spot candidate region in the i + 1 frame, and Ii is the average luminance of the i-frame portion corresponding to the black spot candidate region. Further, σi + 1 is the standard deviation of the luminance in the region of the black spot candidate in the i + 1 frame, and σi is the standard deviation of the luminance in the portion of the i frame.

Since the contrast medium is injected into the blood vessel for which the vascular tomographic image is taken during the pullback, the brightness of the image of the blood vessel becomes low. In step S505, the blood vessel detection unit 302 automatically traces the marker position determined in step S504, that is, from the position of the X-ray opaque marker 118 to the blood vessel base so as to pass through the portion having a low brightness value. The coordinate value sequence on the blood vessel obtained by the trace is held in the blood vessel position information storage unit 304 as the blood vessel position information, and is used in the position conversion table generation process (step S402) described later. As the blood vessel base, the end position of the guiding catheter 112 is used. Since the end position of the guiding catheter 112 provides a characteristic image on the X-ray image, the blood vessel detection unit 302 can automatically detect this end position, that is, the blood vessel base. The range from the blood vessel base thus obtained to the X-ray opaque marker is the imaging range of the vascular tomographic image.

FIG. 6A is a diagram for explaining the blood vessel position information obtained in step S505. The x and y coordinate values of the corresponding points on the blood vessel obtained by automatic tracing from the marker position 602, which is the detection position of the X-ray opaque marker 118, to the blood vessel base 603, which is the end of the guiding catheter 112, are blood vessels. It is retained as position information. In the example of FIG. 6A, the case where p corresponding points are acquired in the automatic trace from the marker position 602 to the blood vessel base 603 is shown, and p coordinates are acquired as the blood vessel position information. The state is shown.

Next, in step S506, the blood vessel detection unit 302 determines whether or not the processed X-ray image is the final frame (whether or not the X-ray image of the above-mentioned M frame is processed). If it is determined that it is the final frame, this process ends. If it is determined that it is not the final frame, the process proceeds to step S507.

In step S507, the blood vessel detection unit 302 causes the X-ray image reading unit 301 to read the next frame of the X-ray image group 322. Then, in step S508, the blood vessel detection unit 302 tracks the blood vessel using the blood vessel position information (blood vessel position information acquired in step S505) of the immediately preceding X-ray image with respect to the X-ray image acquired in step S507. Do. The blood vessels displayed on the X-ray image have different positions on the image between frames due to the influence of heartbeat and the like. This movement can generally be expressed by translation and rotation. Therefore, blood vessel tracking processing between frames is performed using a well-known image tracking algorithm such as the AKAZE algorithm having robust characteristics.

Next, in step S509, the blood vessel detection unit 302 calculates the marker estimation position in the X-ray image read in step S507. More specifically, the blood vessel detection unit 302 moves the position on the blood vessel detected by the blood vessel tracking process to the base side by a predetermined interval from the position corresponding to the marker position detected in the immediately preceding frame in the next frame. It is calculated as the estimated position of the marker in. Here, the predetermined interval for moving the marker position can be determined from, for example, the pullback speed of the probe 115. Alternatively, the user may specify the marker position for the first few images of the X-ray image group 321 and calculate a predetermined interval from the interval of the specified position.

When the estimated position of the marker is obtained in step S509, the process returns to step S502. As the estimated position of the marker in the subsequent step S502, the marker estimated position calculated in step S509 is used instead of the initial marker position specified by the user. As described above, when the blood vessel detection is completed for the X-ray image of the M frame in the X-ray image group 322 taken during the pullback (YES in step S506), the blood vessel detection process shown in FIG. 5 is completed. , The process proceeds from step S401 to step S402.

In step S402, the table generation unit 303 generates and converts a conversion table in which the vascular tomographic image and the imaged position in the X-ray image are associated with each X-ray image of the X-ray image group 322 taken during the pullback. It is stored in the table storage unit 305. Hereinafter, the conversion table generation process by the table generation unit 303 will be described with reference to the flowchart of FIG. 7A.

First, the variable m is set to 1 in step S701. Next, in step S702, the table generation unit 303 acquires the blood vessel position information of the m-th X-ray image of the X-ray image of the M frame from the blood vessel position information storage unit 304. Then, in step S703, the table generation unit 303 calculates the blood vessel length L (the length from the marker position to the blood vessel base) of the target blood vessel detected by the blood vessel detection process based on the blood vessel position information. The blood vessel length L is obtained by calculating the linear distance between adjacent corresponding points of the blood vessel position information and integrating them. For example, when the blood vessel position information has p coordinate values as shown in FIG. 6A, the blood vessel length L in the imaging range from the marker position to the blood vessel base (guided catheter end) is calculated by the following [Equation 1]. To.

Next, in step S704, the table generation unit 303 samples the blood vessel length L obtained in step S703 so as to be equally divided by the number of frames of the blood vessel tomographic image. That is, the positions corresponding to the acquisition positions of the vascular tomographic images are set so as to line up at equal intervals in the imaging range. In the present embodiment, the table generation unit 303 obtains the sampling position by equally dividing the total length L by the number of acquisition positions of the blood vessel tomographic image existing between the marker position of the m-th X-ray image and the blood vessel base side. For example, in the case of the first X-ray image, since the acquisition positions of all N frames tomographic images are included between the marker position and the blood vessel base, the sampling position interval dL (= L / (N-1)). ) Is obtained. More generalized, between the marker position of the blood vessel and the base of the blood vessel in the m-th X-ray image of the X-frame, [(N / M) × (m-1) of the vascular tomographic image of the N frame ) +1] There are acquisition positions of vascular tomographic images from the 5th frame to the Nth frame. Therefore, in the m-frame X-ray image, the number of frames of the vascular tomographic image in which the acquired position exists between the marker position and the blood vessel base is N'= N- (N / M) × (m-1), and sampling is performed. The position interval is dL = L / N'. This is shown in FIG. 6B.

Next, in step S705, the table generation unit 303 acquires the coordinates on the X-ray image corresponding to the acquisition position of each blood vessel tomographic image based on the interval of the sampling position, and generates a conversion table by associating them. Then, it is stored in the conversion table storage unit 305. The coordinate values are obtained, for example, as follows.

The coordinate position on the X-ray image of the i-th blood vessel tomographic image is acquired based on the coordinate values immediately before or after dL × i among the p coordinate values of the blood vessel position information. For example, the jth or j + 1th coordinate value satisfying the following [Equation 2] among the p coordinate values of the blood vessel information is used as the coordinate value corresponding to the acquisition position of the i-th blood vessel tomographic image.

Alternatively, the acquisition position of the vascular tomographic image may be determined on the line segment connecting the jth and j + 1th coordinate values satisfying [Equation 2]. For example, as shown in FIG. 6B, when the blood vessel length up to the jth coordinate in the blood vessel information is L1, from the jth coordinate value on the line segment connecting the jth and j + 1th coordinates. A coordinate value at a distance of dL × i−L1 may be used as a coordinate value corresponding to the acquisition position of the i-th blood vessel tomographic image.

The table generation unit 303 stores the blood vessel tomographic image obtained as described above and the acquisition position (coordinate value) on the X-ray image as a conversion table in the conversion table storage unit 305. In step S706, the table generation unit 303 determines whether or not the processing has been completed for the final frame (Mth frame) of the X-ray image group 322, and if there is an unprocessed frame, the processing proceeds to step S707. After one m is added in step S707, the process returns to step S702. In this way, the above-mentioned conversion table generation process is executed for the next X-ray image. When it is determined that the final frame has been processed in step S706, the conversion table generation process ends. As a result, as shown in FIG. 7B, the conversion table storage unit 305 stores M conversion table groups 710 corresponding to the M X-ray images of the X-ray image group 322.

When the conversion table is generated for each X-ray image, the process proceeds from step S402 to step 403. In step S403, the display control unit 307 synchronously displays the X-ray image and the vascular tomographic image, and superimposes and displays the cross-sectional information on the X-ray image. In the present embodiment, an M-frame X-ray image corresponding to the N-frame vascular tomographic image can be obtained according to the frame rate of the vascular tomographic image by the intravascular diagnostic apparatus 100 and the frame rate of the X-ray image by the X-ray imaging apparatus 200. .. Therefore, it is possible to easily determine which number of the vascular tomographic image corresponds to the number of the acquisition timing of the X-ray image. In the synchronous display, the vascular tomographic image and the X-ray image whose acquisition timings correspond to each other are displayed at the same time.

The synchronous display in step S403 and the superimposed display of the cross-sectional information will be described with reference to the flowchart of FIG. Hereinafter, a case where an X-ray image to be displayed on the display 308 is specified, a vascular tomographic image corresponding to the X-ray image is read out, and synchronous display is realized will be described. However, it goes without saying that the vascular tomographic image to be displayed on the display 308 may be designated, and the corresponding X-ray image may be read out to realize the synchronized display.

In step S801, the display control unit 307 acquires the designated X-ray image from the X-ray image storage unit 106 via the X-ray image reading unit 301 and displays it on the display 308. In step S802, the display control unit 307 transmits the vascular tomographic image (vascular tomographic image corresponding to the acquisition timing of the X-ray image) of the vascular tomographic image acquired in step S801 via the vascular tomographic image reading unit 306. It is acquired from the image storage unit 105 and displayed on the display 308. In this way, the X-ray image and the vascular tomographic image are displayed in synchronization.

Next, in step S803, the display control unit 307 acquires a conversion table corresponding to the X-ray image being displayed from the conversion table storage unit 305. In step S804, the display control unit 307 acquires the frame number of the blood vessel cross-sectional image associated with the item of the cross-sectional information to be displayed. It is desirable that the user can specify the item of the cross-section information to be displayed. For example, suppose that the peripheral side position and the base side position of the reference are specified as items of cross-section information to be displayed. In this case, the display control unit 307 has a frame number of the vascular tomographic image to which information indicating the base side of the reference is attached as cross-sectional information and a frame number of the vascular tomographic image to which information indicating the peripheral side of the reference is attached. To get.

In step S805, the display control unit 307 refers to the conversion table acquired in step S803 and obtains the coordinate values corresponding to the frame numbers acquired in step S804. In step S806, the display control unit 307 superimposes and displays the cross-sectional information on the X-ray image based on the acquired coordinate position. For example, when the reference position is designated as the cross-sectional information to be superimposed and displayed, the display control unit 307 is designated as the reference position with reference to the cross-sectional information of the blood vessel tomographic image stored in the blood vessel tomographic image storage unit 105. Obtain the most peripheral frame number and the most base frame number of the existing vascular tomographic images. Then, the display control unit 307 refers to the conversion table obtained in step S803, acquires the coordinate values on the X-image corresponding to those frame numbers, and displays on the X-ray image indicating the start position of the reference. Do.

FIG. 9 is a diagram showing an example of synchronous display of the above-mentioned blood vessel tomographic image and X-ray image, and an example of superimposition display of cross-sectional information. In FIG. 9, the X-ray image 900 is the X-ray image acquired in step S801, and the vascular tomographic image 920 is the vascular tomographic image acquired in step S802. The vertical cross-sectional image 940 is a diagram showing a cross section in the blood vessel length direction generated by using a group of vascular tomographic images in a predetermined range including a vascular tomographic image 920. In the X-ray image 900, the mark 910 is the acquisition position (M) of the vascular tomographic image 920, and coincides with the mark position detected on the X-ray image 900. The vertical cross-sectional image 940 is, for example, a cross-sectional view obtained by cutting out a predetermined length centered on the acquisition position (M) of the vascular tomographic image 920.

In FIG. 9, the X-ray image 900 shows an example of superimposed display of the reference position described above. The base side (P) and peripheral side (D) reference positions obtained as described above are indicated by marks 901 and 902 on the X-ray image 900. The marks 901 and 902 are figures indicating the positions on the blood vessel image corresponding to the acquisition positions of the vascular tomographic images at the reference positions on the base side and the peripheral side. The mark 901 is a line segment having a predetermined length arranged so that the coordinate value corresponding to the frame number on the base side is the center, and the direction thereof is the coordinate value of the blood vessel position information at both ends of the coordinate value as both ends. It is designed to be orthogonal to the direction of the line segment. Similarly, the mark 902 on the peripheral side is a line segment having a predetermined length arranged so that the coordinate value corresponding to the frame number on the peripheral side is the center, and the direction is the blood vessel position information at both ends of the coordinate value. It is orthogonal to the direction of the line segment whose ends are the coordinate values. By such superimposition display, the reference position on the base side and the reference position on the peripheral side are clarified, and the lesion section or the like designated by the doctor using the vascular tomographic image group is clarified on the X-ray image. The cross-sectional information (chamber area, average lumen diameter, etc.) associated with the frame at the reference position on the base side and the peripheral side may be displayed by the boxes 903 and 904, respectively. Also in the vertical cross-sectional image 940, the position of the vascular tomographic image corresponding to the reference position on the base side and the peripheral side and the position corresponding to the vascular tomographic image 920 are shown as marks 941, 942, 943, respectively. ..

FIG. 10A is a display example when a state related to calcification is selected as an item of cross-sectional information to be superimposed and displayed. In FIG. 10A, the vascular tomographic image 920 and the longitudinal sectional image 940 that are displayed synchronously are omitted. For example, when instructed to display the cross-sectional information regarding the "calcification thickness", the display control unit 307 searches for the cross-sectional information in which the "calcification thickness" is recorded, and determines the thickness distribution. Displayed by bar 911. The display range of the bar 911 is between the position 912 of the frame number on the most base side and the position 913 of the frame number on the most peripheral side of the frame having the cross-sectional information in which the thickness of calcification is described. The bars 911 are classified by color or density according to the cross-sectional information (calcification thickness), and the doctor can know the distribution of the calcification thickness by the bar 911. If the "calcification thickness" is not described in the cross-sectional information related to the frame of the display range of the bar 911, the color or density is determined by interpolating from other cross-sectional information. The "calcification angle" can be displayed in the same manner as the bar 911. In FIG. 10A, the bar 911 is displayed together with the display of the reference position, but the display related to the reference position may not be performed.

FIG. 10B is a display example of an X-ray image when both end positions of the region where the indwelling stent exists are specified as the item of the cross-sectional information to be superimposed and displayed. The display control unit 307 acquires the frame number on the most base side and the frame number on the most peripheral side among the vascular tomographic images associated with the cross-sectional information in which the stent is described to be present. Then, the display control unit 307 acquires the corresponding coordinate values with reference to the position conversion table, and marks both ends of the range in which the stent exists with marks 914 and 915. For example, a bioabsorbable stent (BRS) is difficult to be reflected in an X-ray image and its location is difficult to be confirmed even by looking at an X-ray image, but it is relatively clear and easy to detect in a vascular tomographic image. Therefore, according to such a superposed display, the location of the bioabsorbable stent (BRS), which is difficult to be seen in the X-ray image, is clarified, which is effective for postoperative diagnosis and the like. In FIG. 10B, the range where the stent exists is displayed together with the display of the reference position, but the display regarding the reference position may not be performed.

The above is an example of superimposed display, and various cross-sectional information can be displayed at corresponding positions on the X-ray image. In the above, the information based on the cross-sectional information is superimposed and displayed on the X-ray image based on the acquisition position of the corresponding vascular tomographic image, but the information based on the cross-sectional information does not necessarily have to be superimposed and displayed. For example, in FIGS. 9, 10A, and 10B, the contents displayed in the boxes 903 and 904 may be displayed in an area other than the display area of the X-ray image, such as the vertical cross-sectional image 940.

Further, as information based on the cross-sectional information, distance information indicating the distance (length) along the blood vessel between two points on the blood vessel image may be displayed. In this case, for example, as the cross-sectional information (information to be automatically detected) in FIG. 3B, the blood vessel from the reference position (for example, the position of the head vascular tomographic image = the marker position on the X-ray image corresponding to the head vascular tomographic image) The distance along (dL × i in FIG. 6B) is maintained. The display control unit 307 obtains the distance (length) along the blood vessel from the difference in the distance included in the cross-sectional information associated with the vascular tomographic image corresponding to the two positions on the blood vessel image, and obtains the distance (length) along the blood vessel to obtain the cross-sectional information. Display as based information. For example, in FIG. 9, the display control unit 307 acquires the length along the blood vessel between the mark 901 and the mark 902 from the cross-sectional information (distance) associated with the blood vessel tomographic image corresponding to each position. This can be superimposed and displayed on the X-ray image, or displayed on the vertical cross-sectional image 940.

Further, the use of the position conversion table is not limited to the above-mentioned superimposed display. Since the frame number of the vascular tomographic image and the coordinates on the X-ray image are associated with each other in the position conversion table, for example, specify an arbitrary position on the blood vessel image of the blood vessel to which the probe on the X-ray image has moved. Then, the corresponding vascular tomographic image can be displayed. For example, in FIG. 9, when the mark 910 is moved to an arbitrary position on the blood vessel by a mouse operation or the like on the X-ray image 900, the display control unit 307 calculates the coordinate value of the moved mark 910. Then, the display control unit 307 acquires the frame number associated with the coordinate value closest to the calculated coordinate value in the position conversion table, and stores the acquired vascular tomographic image after the frame plate in the vascular tomographic image storage unit. Read from 105 and display. In this way, on the X-ray image, the user's designated position on the blood vessel image can be detected, and the blood vessel tomographic image at the acquisition position closest to the detected designated position can be selected and displayed. Alternatively, by designating any two points on the blood vessel image of the blood vessel to which the probe has moved, based on the distance information included in the cross-sectional information associated with the blood vessel tomographic image with the designated two points as the acquisition positions. , The distance along the blood vessel can also be calculated and displayed.

In this case, the tomographic image may be sequentially acquired and displayed according to the moving position of the mark 910, or the corresponding vascular tomographic image may be acquired after the position of the mark 910 after the movement is determined. You may. However, if the X-ray image is immediately synchronized according to the vascular tomographic image that is switched during the movement of the mark 910, the user who moves the mark 910 is confused, so it is desirable to stop the synchronized display of the X-ray image. Therefore, it is desirable not to update the display of the X-ray image while the position designated by the user changes at intervals shorter than a predetermined time. In that case, after confirming that the mark 910 has stopped for a predetermined time, the display may be switched to the X-ray image corresponding to the vascular tomographic image being displayed, and the synchronous display may be restarted. Alternatively, after the mark 910 is moved, the synchronous display of the X-ray image may be restarted in response to a predetermined user operation.

Further, in the above embodiment, a position conversion table is generated in advance for all X-ray images during the imaging period of the vascular tomographic image, and a position corresponding to the acquired position of the specified vascular tomographic image is obtained. It is not limited. For the X-ray image selected as the display target, each time the vascular tomographic image corresponding to the cross-sectional information to be superimposed is specified, the position on the vascular image corresponding to the acquired position of the specified vascular tomographic image is determined. You may. Alternatively, each time the X-ray image to be displayed is determined, the above-mentioned position conversion table may be generated for the X-ray image.

According to the above embodiment, for example, the lesion range confirmed by the vascular tomographic image can be superimposed and displayed on the X-ray image. Therefore, the lesion site confirmed by the vascular tomographic image on the X image that the doctor wanted to confirm is visualized, and it is possible to speed up the treatment strategy planning and facilitate the treatment.

The present invention is not limited to the above embodiments, and various modifications and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.

This application claims priority based on Japanese Patent Application No. 2016-012768 submitted on January 26, 2016, and all the contents thereof are incorporated herein by reference.

Claims (18)

An access means for accessing a storage means for storing a plurality of vascular tomographic images acquired while moving the probe in the axial direction of the catheter and a plurality of X-ray images taken during the movement of the probe.
An acquisition means for acquiring an X-ray image to be displayed from the plurality of X-ray images via the access means, and an acquisition means.
A specific means for identifying a vascular tomographic image from the plurality of vascular tomographic images, and
In the X-ray image to be displayed, a determination means for determining a position corresponding to the acquisition position of the specified blood vessel tomographic image on the blood vessel image corresponding to the blood vessel to which the probe has moved, and
A predetermined figure is superimposed and displayed on the X-ray image to be displayed so as to indicate the position determined by the determination means, and information based on the cross-sectional information associated with the vascular tomographic image identified by the specific means is displayed. Display control means to be displayed on the means and
A detection means for detecting a user-designated position on the blood vessel image on the X-ray image, and
With
The display control means
The vascular tomographic image of the acquisition position closest to the designated position detected by the detection means is selected from the plurality of vascular tomographic images and displayed.
An X-ray image corresponding to the acquisition timing of the vascular tomographic image at the acquisition position closest to the designated position is selected from the plurality of X-ray images and displayed.
An image display device, characterized in that the display of the X-ray image is not updated while the designated position changes at intervals shorter than a predetermined time. The determination means is
A position conversion table in which the positions corresponding to the acquisition positions of the plurality of blood vessel tomographic images on the blood vessel image of the X-ray image to be displayed are recorded is generated.
The image display device according to claim 1, wherein a position corresponding to an acquisition position of the specified vascular tomographic image is determined by referring to the position conversion table. The determination means is
A position conversion table is generated and held in advance for each of the plurality of X-ray images.
The image display device according to claim 2, wherein the corresponding position in the X-ray image to be displayed is determined by selecting and referring to the position conversion table of the X-ray image to be displayed. The determination means is
The imaging range of the vascular tomographic image is specified in the blood vessel image to which the probe has moved in the X-ray image.
Claims 1 to 1, wherein a plurality of acquisition positions of a blood vessel tomographic image corresponding to the imaging range are determined at equal intervals in the imaging range, and corresponding positions on the blood vessel image are determined. The image display device according to any one of 3. The image display according to claim 4, wherein the imaging range is a range from the position of the X-ray opaque marker provided on the probe to the position of the end portion of the guiding catheter in the blood vessel image. apparatus. The display control means selects a vascular tomographic image corresponding to the acquisition timing of the X-ray image to be displayed from the plurality of vascular tomographic images, and performs synchronous display to be displayed together with the X-ray image to be displayed. The image display device according to any one of claims 1 to 5, which is characterized. The specific means is characterized in that it identifies a vascular tomographic image at a reference position on the base side and a vascular tomographic image at a reference position on the peripheral side based on the cross-sectional information associated with the plurality of vascular tomographic images. Item 6. The image display device according to any one of Items 1 to 6. The identification means identifies a vascular tomographic image on the base side of one branch and a vascular tomographic image on the peripheral side of the one branch based on the cross-sectional information associated with the plurality of vascular tomographic images. The image display device according to any one of claims 1 to 7, wherein the image display device is characterized by the above. One of claims 1 to 8, wherein the specific means identifies a vascular tomographic image at both ends of an indwelling stent based on cross-sectional information associated with the plurality of vascular tomographic images. The image display device described in 1. The display control means displays at least one of the lumen area, the average diameter of the lumen, the maximum diameter, the minimum diameter, and the degree of eccentricity from the cross-sectional information associated with the vascular tomographic image specified by the specific means. The image display device according to any one of claims 1 to 9, wherein the image display device. The specific means according to any one of claims 1 to 10, wherein the user identifies a bookmarked blood vessel tomographic image based on the cross-sectional information associated with the plurality of blood vessel tomographic images. Image display device. The display control means is characterized in that information based on the cross-sectional information associated with the vascular tomographic image identified by the specific means is superimposed and displayed on the X-ray image based on the position determined by the determination means. The image display device according to any one of claims 1 to 11. The identification means identifies a vascular tomographic image associated with cross-sectional information having information indicating the thickness of calcification or the angle of calcification.
The display control means displays a display representing the distribution of calcification thickness or the distribution of calcification angle on the blood vessel image based on the position corresponding to the acquisition position of the specified vascular tomographic image. The image display device according to any one of claims 1 to 12, wherein the image is superimposed on an X-ray image. When it is confirmed that the designated position has been stationary for a predetermined time, or when a predetermined user operation is performed, an X-ray image is displayed according to the acquisition timing of the vascular tomographic image at the acquisition position closest to the designated position. The image display device according to any one of claims 1 to 13, wherein the image display device. The cross-sectional information includes distance information indicating the distance along the blood vessel from the reference position to the acquisition position of the vascular tomographic image.
Claims 1 to 1, wherein the display control means displays the distance between the two vascular tomographic images based on the distance information associated with the two vascular tomographic images identified by the specific means. 14. The image display device according to any one of 14. The image display device according to claim 15, wherein the specific means identifies a vascular tomographic image corresponding to a position specified by a user on a blood vessel image of a blood vessel to which the probe has moved in the X-ray image. .. It is a control method of the image display device.
The plurality of X-rays are accessed by accessing a storage means that stores a plurality of vascular tomographic images acquired while moving the probe in the axial direction of the catheter and a plurality of X-ray images taken during the movement of the probe. The acquisition process to acquire the X-ray image to be displayed from the image, and
A specific step of identifying a vascular tomographic image from the plurality of vascular tomographic images, and
In the X-ray image to be displayed, a determination step of determining a position corresponding to the acquisition position of the specified blood vessel tomographic image on the blood vessel image corresponding to the blood vessel to which the probe has moved, and a determination step.
A predetermined figure is superimposed and displayed on the X-ray image to be displayed so as to indicate the position determined in the determination step, and information based on the cross-sectional information associated with the vascular tomographic image identified in the specific step is displayed. The display control process to be displayed on the means and
A detection step of detecting a user-designated position on the blood vessel image on the X-ray image, and
Have,
The display control step is
A step of selecting and displaying a vascular tomographic image of an acquisition position closest to a designated position detected in the detection step from the plurality of vascular tomographic images, and a step of displaying the vascular tomographic image.
A step of selecting and displaying an X-ray image corresponding to the acquisition timing of the vascular tomographic image at the acquisition position closest to the designated position from the plurality of X-ray images, and
A control method for an image display device, which comprises a step of not updating the display of the X-ray image while the designated position changes at intervals shorter than a predetermined time. A program for causing a computer to execute each step of the control method of the image display device according to claim 17.

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